<?php
class Music {
    public function open(){
        echo "打开功放<br>";
    }
    public function changeDvd() {
        echo "功放输入切换dvd<br>";
    }
    public function setRound() {
        echo "功放设为环绕立体声<br>";
    }
    public function setSound() {
        echo "功放声音调中<br>";
    }
    public function close() {
        echo "关闭功放<br>";
    }
}